LCKLSL, an N-terminal hexapeptide, acts as a competitive inhibitor of annexin A2 (AnxA2), effectively preventing the binding of tissue plasminogen activator (tPA) to AnxA2 while also inhibiting the generation of plasmin. In addition, LCKLSL exhibits anti-angiogenic properties.

In human retinal microvascular endothelial cells (RMVECs), administering LCKLSL at doses of 0 to 2 mg reduces plasmin production and decreases the activity of tissue plasminogen activator (tPA) stimulated by vascular endothelial growth factor (VEGF) under hypoxia conditions[1].

Utilizing LCKLSL in two in vivo models (in chicken chorioallantoic membrane and murine Matrigel plug assays) for studying angiogenesis has shown to inhibit angiogenic responses. Administering the LCKLSL peptide considerably reduces vascular length. Furthermore, at a concentration of 5 μg/mL, it markedly diminishes vascular branch, junction, and end-point counts[1].